Yes, there are a number of brew pubs that brew strong ale, The Frog and Parrot pub in Sheffield that produces Roger and Out is generally regarded as the strongest.
I have to say however, that if it's that sought of nightcap that is your preferred tipple, try the beers from Belgium. The weakest start at 5%(the fruit and wheat beers) and the strongest (typically the 'Abbey' or 'Trapist' beers) rise to around 14%. Far more paletable than the syruppy(sp) beers of that potency from this country.
Lesson ends.